Calculating device



F.-H. SEELY, CALCULATING DEVICE.

APPLICATION FILED FEB H. I920.

Patented July 5, 1921.

WITNESS ATTORNEYS UNITED STATES PATENT OFFICE.

FRANK HOWARD SEELY, OF OAKLAND, CALIFORNiA.

CALCULATING DEVICE.

To all whom it may concern."

Be it known that I, FRANK HOWARD SEELY,

a citizen of the Umted States, residing at the principle of the movable logarithmic scale, or slide rule, and while the same is adapted for use in connection with the solving of problems generally, it is illustrated specifically for the purpose of obtaining at a single operation the product of three or more factors, especially in cases where such result is in a unit different from that of the factors themselves; for example, when em: ployed in connection with one form of chart to obtain with one operation the 'cub1c measurementin feet and fractions thereof, of a container whose dimensions are in inches (multiplying three factors and dividing by 1728) to obtain with one operation the capacity in gallons of a round container whose height and diameter are given in inches (multiplying four factors and dividing by 230 To accomp ish these results I provide a device which in its simplest form may be roughly described as a slide rule associated with a T square moving across a board on which is contained or mounted a chart. The novelty consists in the above combination, which increases the capacity of the slide rule, and the arrangement of scales on the chart, the whole performing a new function, and solving problems that have hitherto required several operations or the use of bulky mathematical tables.

With the above mentioned and other objects in view, the invention consists in the novel construction and combination of parts hereinafter described, illustrated in the accompanying drawings and pointed out in the claim hereto appended; it being under stood that various changes in the form, proportion, size and minor details of construction Within the scope of the claim may be resorted to without departing from the spirit or sacrificing any of the advantages of the invention.

I shall describe in detail a form of my invention which I'have found to be convenient and practical, but do not confine Specification of Letters Patent.

.to utilize an Patented July 5,1921.

Application filed February 14, 1920. Serial No. 858,749.

myself to strict adherence to'the details of construction herein described, feeling free convenient form which will accomplish t e purpose stated and'is substantially as set forth.

To more fully comprehend theinvention referencexis directed to the accompanying drawings, wherein v,

Figure 1 is a view in plan ofthe preferred embodiment of the invention." I i Fig. 2 is a view in perspective of vention with the chart removed from the board.

Fig. 3 is a cross sectional view taken on line 3--3 of Fig. 1. l v

Fig. 4 is a broken sectional view of the device taken on line 1-4: of Fig. 1. Referring more particularly to the draw ings, wherein like characters of reference designate corresponding parts,-1 is a board,

such as an ordinar drawing board. ,2 is a rule whlch I designate as the movable rule, and which moves latitudinally, or

up and down upon the board 1. .3, "I;

designate asthe sliding rule. It is mounted upon the movable rule 2 in such manner as .to movelongitudinally, or back and forth across the surface of the board 1.

A simple and convenient mode ofconthe instruction is the following. A plate 4, preferably of thin metal, is attached rigidly, in any suitable manner, to guides 5, arranged one at each end of the member .2. The guides 5 are so placed as to hold the movable rule 2 firmly in place across the surface of the board 1, and at the same. time permit it to slide freely up and down thereover without lateral play. In the ends or a logarithmicscale. A like scale is on the sliding rule 3, which moves with one edge in contact with that of rule 8 and is suitably secured to rule 2 so as to slide freel The scale on 3, however, is not against t e scale on 8, but on the upper edge 8, which is thin. As scale 3 is of the same width as the exposed portion of plate 4, the scale on 3 is close to the surface of board 1. The only point of contact between scale 8 and scale 3 is the guide line 8 on scale 3.

Plate 4 is kept from actual rubbing contact with board 1 by shoulders 9'.

In this particular embodiment of the in.- vention, a chart 9 is attached to the surface of board 1, and the same is-so marked by lines, points or ii res as to express the result of the multiplication of two factors j by means of the logarithmic scales 3 and 8,

(commonly called inches). This involves multiplying the three factors together, dividing the result b 1728 to get the cubic feet and dividing t e remainder by 144.- to get the inches. It is a long and tedious process, and shippers are accustomed to use a bulky book of tables.

With my device the same result is reached as follows. Place the edge of plate 4 on the line that corresponds with one of the dimensions of the package, as shown at the left hand side of chart 9. -Mo.ve sliding rule 3 so that the guide line 8 is opposite another dimension; then find in scale 3 the third dimension; and on table 9 at that point will be the result in cubic feet and inches.

In Fig. 1, movable rule 2 is so placed that the dimension 21 is indicated at the left hand margin. The dimension 10 is indicated by the position of guide line 8 on rule 3. The third dimension is to, be read on scale 3. If, for instance, the third dimen sion should be 25, the reading on table 9 would indicate 3, which means that a package 10" x21" x 25 would measure a little over three cubic feet, which is correct, the actual mathematical measurement being 3.038 feet, or, in the language of the shipper three feet and half an Inch.

Other uses of the device will occur. to those interested in the solution of problems of this character;

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is j -A device of the character described comprising a supporting base having enlarged end portions provided with guiding grooves within the outer surfaces thereof, a freely slidable main rule ada ted to move over said base, and a guide b 001; secured to each end of said rule havin proiections riding within the recesses of t e on arged ends of the base, said rule having its up er surface formed to provide a raised a uated surface and a s ace bordered y "said raised graduated sur ace, a movable rule positioned within said space of a length less than the length of the main rule and having its upper surface lying flush with the surface -'of the raised graduated portion of the main rule, said movable rule being graduated and slidable relative to the main rule.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

' FRANK HOWARD SEELY. Witnesses: r

N. A. AoKER,

S. CoNs'rINE. 

